a. Field of the Invention
This invention relates to a method of making a container having a separable inner lining and outer shell, the inner layer being adhered to the outer layer such that after use, the inner layer may be peeled away from the outer layer. In particular, this invention relates to a container for a beverage or foodstuff, and to a container for paint or other potentially hazardous liquids.
b. Related Art
There is a general desire and need to reduce the amount of waste that is produced and a drive to recycle as much as possible. One particular area that is receiving much attention is packaging.
One sector of interest is disposable or paper cups. These are often made from pre-laminated card which is then rolled and formed to create a disposable cup. The use of laminated card can have the benefits of being more resource and energy efficient than using plastic alone, however, combining materials in this way makes recycling difficult, and therefore, most disposable cups end up in landfill.
Typically the laminated card comprises a paper-based substrate layer and a polymeric coating, which in the case of disposable cup is usually polyethylene. The coating is waterproof and acts as a liquid barrier between the contents of the cup and the paper-based substrate. Generally, the laminated card has a polymeric or plastics coating on only one side of the substrate when used to form cups to hold hot beverages, whereas the laminated card will often have a plastics coating on both sides of the paper-based substrate when used to form cups to hold cold beverages.
However, these coatings prevent the material from fully decomposing. In particular, during the recycling process typically used for paper products, the plastics coating prevents or inhibits water breaking up the paper fibres of the substrate during the process of pulping. Additionally, the plastics coating is difficult to separate and therefore contaminates the paper pulp that is formed.
Of note is the fact that an estimated 58 billion paper cups end up in landfill every year in the USA, and this equates to several million trees being felled annually, as most of the paper-based material used to form the cups is virgin, non-recycled material.
There is, therefore, a need to find a more environmentally friendly alternative. However, commercial considerations mean that it is desirable for any alternative to be able to be manufactured at similar speeds and in similar volumes to existing paper cups and also with the same degree of reliability and consistency. Current paper cup making machines typically output at a rate of up to 100-200 cups per minute with a failure/leakage rate of about one cup in every million.
A second sector of interest is that of containers for hazardous liquids such as paints and oils. Containers for hazardous liquids are difficult to dispose of in an environmentally safe manner and very few containers are recycled due to contamination by the paint, oil or other similar substance.
Known paint pots and similar containers filled with environmentally hazardous liquids are typically made from a semi-rigid plastics material or from metal. After use, the pot remains contaminated with paint residue or similar and the entire container must be disposed of in a suitable manner depending on the type of hazardous liquid. Often the containers end up in a specialist landfill. However, the cost associated with dealing with these containers means that it is becoming increasingly difficult to dispose of them in a convenient and cost effective way.
It is, therefore an object of the invention to provide a container, and a method of making such a container, that overcomes the above-mentioned problems.